PLANT REPRODUCTION 161 



ease of this method of reproduction is more pronounced. 

 For example, if an injury occurs to a carnation stem near 

 the base, roots will be formed there quickly, provided mois- 

 ture and temperature conditions are correct. 



127. Texture of material. In selecting material for 

 propagation by cuttings, it is essential that it be of the 

 right degree of maturity. Very recent growth is generally 

 too soft or watery to give good results. The cell structure 

 is not sufficiently firm to develop a root system, and there 

 is not enough reserve food in the tender growth to nourish 

 the cuttings. Therefore, wilting occurs and the cutting 

 dies. Cuttings of new growth are also more likely to be 

 attacked by fungous diseases because of the soft, succulent 

 character of the stem structure. On the other hand, if 

 the tissue is too hard, the protoplasm of the cell contents 

 is more dormant; therefore, bud development goes on 

 slowly. The rooting process is also retarded because of 

 this, and the reserve food in the stem is often exhausted 

 before the new plant is able to absorb nourishment through 

 the root-hairs. Moderately firm structure such as will be 

 found a short distance from the terminal bud should there- 

 fore be chosen for cuttings. 



128. Position on the parent plant. In some cases the 

 part of the plant from which the cutting is taken has a 

 marked influence over the value of the cutting. In the 

 carnation, for example, cuttings taken from near the 

 base of the plant are considered " grassy " by the prop- 

 agator, and at maturity they do not produce sufficient 

 flowers. On the other hand, cuttings taken from the side 

 shoots high on the flower stem produce weak, spindling 

 plants, which quickly shoot up into a flower stalk. There- 

 fore, cuttings taken about halfway up the stem are pre- 

 ferred (Fig. 18, left). -In chrysanthemums, strong 



